Protein kinases have become targets of intense drug discovery efforts for the past 10-15 years (Cohen, Nat. Rev. Drug Discov., 2002, 1(4), 309-315; Sebolt-Leopold, Nature Review Cancer, 2004, 4, 937-947). Small molecule inhibitors of Ras-Raf-Mek-Erk pathway have been the focus of many studies (Thompson, et al., Curr. Opin. Pharmacology, 2005, 5, 1-7; US patent Application 2003/0216446). Raf inhibitors have been proposed to be used in inhibiting cancer cell growth and in the treatment of cancers, including histiocytic lymphoma, lung adenocarcinoma, small-cell lung cancer, pancreatic cancer, and breast cancer. Recently, the approval of Zelboraf® (Vemurafenib by Plexxikon/Roche) for B-Raf mutated metastatic melanoma further demonstrates the attractiveness of the target.
Disruption of VEGFR signaling is a very attractive target in cancer therapy, as angiogenesis is a prerequisite for all solid tumor growth (Folkman, J. National Cancer Institute, 1990, 82, 4-6) and that the mature endothelium remains relatively quiescent (except for female reproductive system and wound healing), consequently, targeting of pro-angiogenesis pathway becomes a strategy being widely pursued to provide new therapeutics in cancer area.
WO2008/115263 to Curis relates to Raf kinase inhibitors containing zinc-binding and their use in the treatment of Raf related diseases and disorders such as cancer. The said derivatives may further act as HDAC inhibitors.
WO2008/033747 to Curis relates to the compositions, methods, and applications of a novel approach to selective inhibition of several cellular or molecular targets with a single small molecule. More specifically, the present invention relates to multi-functional small molecules wherein one functionality is capable of inhibiting histone deacetylases (HDAC) and the other functionality is capable of inhibiting a different cellular or molecular pathway involved in aberrant cell proliferation, differentiation or survival.
WO2009/042646 to Curis relates to the compositions, methods, and applications of a novel approach to selective inhibition of several cellular or molecular targets with a single small molecule. More specifically, the present invention relates to multi-functional small molecules capable of inhibiting a different cellular or molecular pathway involved in aberrant cell proliferation, differentiation or survival.
WO2002/32872 (EP1415987) to Eisai relates to nitrogeneous aromatic ring compounds as anti-cancer agents.
The present invention provides novel cyclopropanecarboxamido-substituted aromatic compounds which have improved anti-tumor activity and longer half-life in vivo over known, structurally-related compounds. These novel compounds are kinase inhibitors, preferably Raf inhibitors and VEGFR-2 (KDR/Flk-1) inhibitors. Since Raf is a key component of Ras-Raf-Mek-Erk pathway and VEGFR-2 is critical in angiogenesis, inhibitors of these kinases will be useful in pharmaceutical compositions for human and veterinary use where inhibition of Raf pathway or VEGFR-mediated angiogenesis is indicated, e.g., treatment of tumor or cancerous cell growth mediated by Raf and/or VEGFR-2 kinases. In particular, the compounds or the invention are useful in the treatment of human and animal solid tumors.